You know what, if I were you I'd make it a simple Xtraction mission. The Imperials realize that their ship is doomed and elect to abandon ship. They need to get the Lambda Class shuttle or Escort Shuttle (even better!) with the officers from the ship to the jump point. The Star Destroyer is moving towards the jump point until she's halted, so the farther the ship can get to the jump point the better. If the Star Destroyer is stopped early, the shuttle will be constantly shot down and will really struggle getting to the jump point. If the cruiser lasts until, say, it's half-way there, however, the shuttle should have a better chance.

So instead of getting the Star Destroyer specifically to Point B, you have to get that shuttle there. A lot more simple, yet much of the same effect.